Control of fine-structure splitting and excitonic binding energies in selected individual InAs/GaAs quantum dots

TL;DR

This study investigates how annealing affects the electronic properties of individual InAs/GaAs quantum dots, revealing significant changes in fine-structure splitting and excitonic binding energies through experimental and theoretical analysis.

Contribution

It provides a systematic experimental and theoretical analysis of annealing effects on quantum dot electronic properties, highlighting changes in wave function shapes and energy levels.

Findings

Significant reduction in excitonic fine-structure splitting after annealing

Dramatic changes in excitonic binding energies observed

Model calculations suggest altered electron and hole wave functions

Abstract

A systematic study of the impact of annealing on the electronic properties of single InAs/GaAs quantum dots (QDs) is presented. Single QD cathodoluminescence spectra are recorded to trace the evolution of one and the same QD over several steps of annealing. A substantial reduction of the excitonic fine-structure splitting upon annealing is observed. In addition, the binding energies of different excitonic complexes change dramatically. The results are compared to model calculations within eight-band k.p theory and the configuration interaction method, suggesting a change of electron and hole wave function shape and relative position.